blkfront: Fix backtrace in del_gendisk

The call to del_gendisk follows an non-refcounted gd->queue
pointer. We release the last ref in blk_cleanup_queue. Fixed by
reordering releases accordingly.

Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 7fa2a1db51e6..3258ae67ac7a 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1021,14 +1021,14 @@ static void blkfront_closing(struct blkfront_info *info)
         /* Flush gnttab callback work. Must be done with no locks held. */
         flush_scheduled_work();
 
-        blk_cleanup_queue(info->rq);
-        info->rq = NULL;
-
         minor = info->gd->first_minor;
         nr_minors = info->gd->minors;
         del_gendisk(info->gd);
         xlbd_release_minors(minor, nr_minors);
 
+        blk_cleanup_queue(info->rq);
+        info->rq = NULL;
+
  out:
         if (info->xbdev)
                 xenbus_frontend_closed(info->xbdev);